It is conventional to adjust the height of the seat of a chair and means are known in which the arms of chairs can be adjusted as to height by incremental or step wise movement. These devices require various manipulative steps such as by ratcheting that actually create substantial difficulty for the seated user. In general, the prior art is exemplified in the U.S. Letters Patent of Spencer 4,085,968, Rei 3,168,346, Spiegelhoff 4,307,913. None of such devices show or suggest remote control manipulation and by a source of stored power or energy built into elements of the chair and extending from the back of the chair.
In the device of Rei an arm for an automotive seat is stored in concealed position and then unfolds for arm rest usage.
In the device of Spencer a hemispheric rest ring is operably supported for the vertical pivot of a chair and requires manual clutch locking of the adjustments for lifting and tilting by someone other than the seated user.
In the device of Speigelhoff the mechanism for adjustment of the arms of a vehicle seat require step-wise manipultion of a ratchet and pawl structure and provides no infinite adjustment. The mechanism is embodied in the rest structure and is articulated with the chair base.
In addition, the seats of the chairs of the prior art reveiwed do not achieve the ergonometric advantages of the present invention.
The principal object of the present invention is to provide a chair with infinite height adjustment of the arms, in normal use ranges, and in which the control for the adjustment is achieved by the user occupying the seat.
Another object is to provide a pantographic mechanism that is powered by a stored source of energy remote from the actuating trigger and in which the control linkage is simple and the power is eccentrically applied. The power is directed into an element in the flanking arms which retain parallelity in all height positions. The arm rests can be selectively set at convenient tilt from horizontal reference.
Another object is to provide a seat and back structure useable with the height adjusted arms in providing optimum ergonometric adjustment to suit substantially all use environments for seating structures and adjusting to substantially all postural problems presented in commercial executive and professional work seating and in relaxation situations as well.
Other objects including simplicity, extended utility, economy of manufacture, and improved overall seating performance will be appreciated by those skilled in the art as the description proceeds.